Adjustable extrusion machine



July 4, 1950 o. w. CARLSON} 2,514,211

ADJUSTABLE EXTRUSION MACHINE Filed March 12, 1947 2 Sheets-Sheet 1 Mia/'1 as 37 25 W 5 W INVENTOK OSCAR W. CAIZLSON ATTORNEYS July 4, 1950 o. w. cARLsoN ADJUSTABLE; EXTRUSION MACHINE 2 Sheets-Sheet 2 Filed March 12,- 1947 l N V E N TO R I oscAxz \MCADLSON ATTORNEYS Patented July 4, 1950 UNITED S.Tr PATENT ()FF ICE 2,514,211,; ADJ USTABLE' EXTRUSION MACHINE 1 Oscar W. Carlson. Cuyahoga. Falls}, Ohio, assignorto The. Firestone Tire i- &; Rubber Company, Akron,.0hio,i a corporation of ,Ohio

Application-March 'lz, 1947;:Seria1 N0;,.-73.4,081;

f invention relates to --tubi-ngor extruding..-

machines especially-to extrusion maohines.. pri

marily; adapted -for forming 0t unvulcaniz'ed' rubber tread-stock. for pneumatic tires.

The formation offtread stock for pneumatic tires-is:one-=prime example'ofuse for the. im'-.

proved-i-extrudingv machine :described -herein, but. 3 itwillbe realized that the-machine canbe used a for: the production of other, continuous-lengths of plastic material to be formeito a desired cross-sectional contour.

for example, being of minimum-depth or thickness inthe marginal areas. Heretofore,.,difierent extrusion heads have been llsediforeach contour,

or, size of tread. desired, although in some, in-

stances, minor deviations .or,variations innthe, treadcontour have been produced by. changing.

the die. plate associated with the extrusionhead.

However, for any. appreciablechange-ln size or. contour of .the extr-udedmaterial, a new extru? of the head previously used -.on the, machine. As. some extruded products --may.. be: several ,inchesjI in thickness and be as much-as..24 Ito .3llfinches in .width substa-ntial extrusion pressures are em-l ployed, .necessitatingextrusion heads of .massive construction Such extrusion heads are usually..-

made fromuacast. metal block which is caree fullymachined andpolishedto the, desired size, with the die surface ,areas ,formed in suchheads being extremely. smooth andof a precise, pref. determined. contour inorder to obtain the de&

due-to-their weightand size, It requires several toshortenthe inoperativetperiod of th'e machine attendant an extrusion head change.

Yet. another object of the inventionvis to ,reduce the number of difierent extrusion heads -requir'ed 'togproduce. agiven number of extruded shapes;

A further and more specific object of the invention, is to, provide. removablebaffies in an extrusion .head'fso as to adapt it to produce any offia. variety of. extrusion contours.

Therforegoingland other objects and advantages-of the invention, which will be made more apparent 1 as the specification, proceeds, are

achieved .bythe provision of the apparatus shown:

inthe accompanying. drawings wherein:

Fig. 1 .is:an;explodedpersp'ective view. of an extrusion ,headembodying the principles of the invention; 1

Figg zis a'pIanvieW oflth'e headof Fig. l;

Fi'lf ,afr'agmentary front elevation of the extrusionfhead of Fig. 1

F'ig. 431s longitudinal vertical section taken on line 14+-4"0f Fig.1 3;". v Fig.5 is-ahorizontal.section through the bafile I member of 'the'invention; sion head-would usuallyhavetto be used inlplace;

menseveral hours to change the extrusion head on a large extrusion machine.

The general objectofthisinvention istoeavoid 5 and overcome. the foregoing and other. disadvantages, of and. objectionstoknown types of exe trusion headsgand to provide .an extrusion head the extrusion head.

. Another. object, of; the. invention is, substamtially to'reducethe amount of-labor involvrad'landI 55w F'ig s'.',6"and 7 arefvertical' sections through. the extreme sizes "of dies that can; beused with an extrusionjheadsuclnas that shown in' Figs. l

Refrringmorein detail to the structureshown.

. the'topjse'ction land the upper surface. of base seotion'j l I are bevelled'at l 9;.and 13 respectively,

through 'ja" central portionthereto, .to define a tapered, wedge-shaped chamber l3a in the ex-.

trusion head. A unitary. removable baffie. or stock'flow control member 20 is removably. positionedfin the chamber formed between the ex-' trusionjheadsections'l I and I8. The extrusion headsectionsll andl8 are usuallymade from.

easily workable cast, metal blocks notnecessarily machined to .highlyaccurate dimensions, wheree as the removable bafflemember 20 is provided with 'a'throat 21 machined to an exact size and] contourtopefiect proper flow, relative to transverse portions of a di'e,1.of plastic material forced therethroug h' to prepare suchlmaterial, for flow through me opening 11. V

Fig.; lclearlys hows that the recess I311. is ape preciably wider and shallower at its. forward or discharge, endthanit isat its;.stock receiving end; andja rectangular; die plate I 5 is secured to.,

3 the base H at its front edge by screws IS. The die plate 15 has a suitably shaped die opening 11 formed therein for forming the extruded material to the desired contour. To complete the external portion of the machine, an upper section It of the extrusion head of the invention is provided and it is adapted to engage with the upper surface of the extrusion head base II to form an extrusion chamber. The upper section [8 is adapted to receive a plurality of cap screws 22 adjusted to bear upon the upper surface of the die plate l5, to aid in securing it in place:

A front or reenforcing member 23 is ordinarily provided to reenforce the die p1ate:l 5, and ity is shown as being pivotally secu'red'to an. arm 24 by a bolt I25 extending from and supported by the extrusion machine iii. Bolts25 and 25aare' provided to secure the upper extrusion head section [8 to the lower section H. through the front member 23 and into the upper section l8 of the extrusion headfor clamping engagement therebetween. Bolts 216a extend through the section 18 and into theextru'sion machine In to secure the extrusionhead section and member 23 to the extrusion machine proper, while bolts I I2 securethe member 23 to thebase'" A primary feature of the invention is that stock flow through the extrusion head of the invention is controlled by the small, easily changed, relatively inexpensive baflie member 20, Fig. 4 of the drawings shows that the member 20 is provided with inwardly extending bafiies 2'! of irregular contour and arranged to effect movement or flow of the stock being extruded from the opening M in circular cross-sectional form to a widened and flat rectangular form in cross section preparatory to flow through the die opening 11. The baiiles 21 are formed as continuations of the surfaces ofthroatZl and are integral with the member 20. Thus, should it be desired to change the size die opening used in the extrusion machine, one would merelyhave to release the front member 23, remove bolts 26a, lift up the extrusion head section 18 and then substitute a new baffle member for that previously used in the machine. A new die plate also would be provided for use in producing the new contour extrusion shape desired. In some instances it may only be necessary to change the shapeof the die opening in the die plate by substitution of die plates, but for any substantial changesin the contour and shape of the material to be extruded, it is necessary to insert anew bafile mem-.

her for that previously used. By using relatively small, removable baffie members for controlling changes in the extruded material, one extrusion head can be adapted to produce a great variety of shapes and sizes of extrudedmaterialfl This. adaptability of the extrusion head. naturally avoids manufacture and stocking of the .widevariety of solid, close tolerance, costly extrusionheads that would be required in accordance with conventional practice prior the present invention. It also is apparent that the labor involved in changing an extrusion head is simplified by the invention since one only need remove afew bolts and lift the extrusion sections apart,- whereas previous practice required that a large,'heavy extrusion head be threadedinto engagement. with the extrusion machine and such action isjmuch more difficult to accomplish than a simple un bolting and lifting action. K

Fig. 4 also indicates that a cooling fluid conduit 28 may be formed in the extrusion machine Bolts 26 extend I for receipt and circulation of suitable coolant therein. A spiral shaped fluid path may also be formed by conduits 29 and 30, in registry in lower and upper sections H and I8 for intercommunication therebetween and with fluid inlet and outlet conduits 3! and 32. A sleeve 33 may be positioned at the mouth 14 of the extrusion machine as shown in Fig. 4, to present an unbroken contour with the surface of throat 2| and baffles 21. Suitable sleeves of varying thickness may be provided for use with the various bafile members employed.

The various members used in practice of the invention naturally would have the same external contoursbut would have widely varying throat 2| and baffles 21 to form the extruded material to any general shape desired. Figs. 6 and '7 illustrate a pair of die plates 35 and 36 usable in tir'etread forming, plate 36 being provided laterally of the tread forming aperture with bores 31 to permit excess stock to flow out of the extrusion chamber. This procedure is desirable in some cases even though the stock flow baflies illustrated and described in detail but the inven-,

,tion is not limited to the specific example, set 35 forth since modification may be resorted to within the scopeof the appended claims.

,What is claimed is:

1. In combination in an extrusion machine having a discharge mouth, a fixed support, an 40..

extrusion head base section adapted to be re movably secured to said support, an extrusion head upper section adapted to be removably associated with said base section and said support,

, said extrusion head sections having correspondmg tapered recesses formed in their associated surfaces to define an extrusion chambensaid extrusion chamber being in communication with and mating with the discharge mouth of the machine and being thicker at its material receiving end than at its discharge end, a hollow one piece extrusion baflie member removably positioned in the extrusion chamber and adapted to receive material forced from the extrusion machine, said baflie member having a plurality of ribs formed therein for shaping plastic material flowing therethrough, and means removably engaging said base section and said upper section to the fixed support whereby said extrusion bafile member is fixedly but removably positioned in the path of flow of the extruded material so a different baiiie member can be substituted when the shape of the extruded material is to truding chamber therewith, means for applying pressure to work material, and a one piece baiiie member removably positioned in the extruding chamber and adapted to receive, transmit and shape work material under pressure, said dividing line being such that the upper section may be lifted free of said baffle member.

3. In an extruding machine, a fixed extruding head section, a removable extruding head section associated with said fixed section and defining therewith a baffle receiving chamber, means associated with said head sections for applying pressure to work material to be forced therethrough, a removable bafile having a work transmitting opening therethrough positioned in said baffle receiving chamber, said head sections being divided along parting surfaces substantially parallel to the direction of flow of said work material, whereby the removable section may be separated from the fixed section to provide access for removing and replacing said baflie in said bafiie receiving chamber.

4. In an extruding machine, separable extruding head sections defining a baffle receiving chamber, means associated with said head sections for applying pressure to Work material to be forced therethrough, a removable baffle having 20 2,061,407

a work material shaping, guiding and transmitting opening therethrough positioned in said baffle receiving chamber, said head sections being divided along parting surfaces substantially parallel to the direction of flow of said work material, whereby the sections may be separated from each other to provide access for removing and replacing said baflie in said baflie receiving chamber.

OSCAR WM. CARLSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS- Number Name Date 1,252,821 Lewis Jan. 8, 1918 1,768,790 Royle July 1, 1930 Royle Nov. 17, 1936 

